Giving bikers even more protection against being hit by cars, the Electrodynamic Bike Light attaches to both wheels and shines forward and backwards to improve visibility at night. Instead of being powered by batteries or friction, like rim mounted dynamos, these use electromagnetic induction. For those who skipped physics class, that means two magnets, in this case neodynium magnets, pass by each other as the wheels spin, which generates current, which then powers the lights.
The only downside is that there's no light when you're not moving, so be careful at those traffic lights. Available now for 18 ($22) for one or 34 ($43) for a pair. Ships out of Copenhagen.